Multistage Electrotherapy Delivered Through Chronically-Implanted Leads Terminates Atrial Fibrillation With Lower Energy Than a Single Biphasic Shock

JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY

卷:63

Article

Janardhan, Ajit H.¹  Gutbrod, Sarah R.²  Li, Wenwen²  Lang, Di²  Schuessler, Richard B.^2,3  Efimov, Igor R.^1,2 

[1] Washington Univ, Dept Med, Div Cardiovasc, Sch Med, St Louis, MO 63130 USA

[2] Washington Univ, Dept Biomed Engn, St Louis, MO 63130 USA

[3] Washington Univ, Sch Med, Dept Surg, Cardiothorac Div, St Louis, MO 63130 USA

关键词: atrial fibrillation;    cardioversion;    defibrillation;    low energy;    multistage electrotherapy;   

DOI  :  10.1016/j.jacc.2013.07.098

来源: Elsevier

【 摘 要 】

Objectives The goal of this study was to develop a low-energy, implantable device-based multistage electrotherapy (MSE) to terminate atrial fibrillation (AF). Background Previous attempts to perform cardioversion of AF by using an implantable device were limited by the pain caused by use of a high-energy single biphasic shock (BPS). Methods Transvenous leads were implanted into the right atrium (RA), coronary sinus, and left pulmonary artery of 14 dogs. Self-sustaining AF was induced by 6 +/- 2 weeks of high-rate RA pacing. Atrial defibrillation thresholds of standard versus experimental electrotherapies were measured in vivo and studied by using optical imaging in vitro. Results The mean AF cycle length (CL) in vivo was 112 +/- 21 ms (534 beats/min). The impedances of the RA-left pulmonary artery and RA-coronary sinus shock vectors were similar (121 +/- 11 Omega vs. 126 +/- 9 Omega; p = 0.27). BPS required 1.48 +/- 0.91 J (165 +/- 34 V) to terminate AF. In contrast, MSE terminated AF with significantly less energy (0.16 +/- 0.16 J; p < 0.001) and significantly lower peak voltage (31.1 +/- 19.3 V; p < 0.001). In vitro optical imaging studies found that AF was maintained by localized foci originating from pulmonary vein-left atrium interfaces. MSE Stage 1 shocks temporarily disrupted localized foci; MSE Stage 2 entrainment shocks continued to silence the localized foci driving AF; and MSE Stage 3 pacing stimuli enabled consistent RA-left atrium activation until sinus rhythm was restored. Conclusions Low-energy MSE significantly reduced the atrial defibrillation thresholds compared with BPS in a canine model of AF. MSE may enable painless, device-based AF therapy. (C) 2014 by the American College of Cardiology Foundation

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